The present inventive concept relates to a photomask cleaning apparatus and methods of cleaning a photomask using the same.
In general, a photolithography process may be used to form a predetermined pattern on a semiconductor substrate. For example, a photoresist pattern may be formed by transferring a pattern of a photomask to a photoresist layer on a semiconductor substrate. Then, a semiconductor substrate or a material layer formed on a semiconductor substrate may be etched using the photoresist pattern to form a predetermined pattern.
The photomask is a mask used to form a photoresist pattern on a semiconductor substrate, and may be configured, generally, by forming a light shielding pattern made of a material such as chromium (Cr) on a transparent substrate such as quartz. The photomask having the light shielding pattern may be exposed to light to transfer an image of the light shielding pattern onto the photoresist on the semiconductor substrate.
In this case, a pellicle for protecting the light shielding pattern may be formed to prevent a foreign substance from adhering to the light shielding pattern formed on the photomask. An adhesive may be used to fix the pellicle onto the photomask. Namely, the pellicle may be adhered to the photomask by using an adhesive.
However, a foreign substance may still adhere to the surface of the pellicle during the photolithography process. Accordingly, it is generally replaced with a new pellicle for the same photomask. In this case, after removing the previously used pellicle, a residue of the pellicle adhesive typically remains on the surface of the photomask that generally should be removed.